Exercise capacity in asymptomatic patients with significant primary mitral regurgitation: independent effect of global longitudinal left ventricular strain

In patients with significant primary mitral regurgitation (MR), previous reports have demonstrated that exercise echocardiography aids in symptom evaluation, risk stratification, decision making (for delaying of surgery, including in those with mid-late systolic MR) (1-3). In addition, decreased functional capacity (FC) on stress testing (4), exercise-induced pulmonary hypertension (5) and MR severity (6) have been associated with worse outcomes. Based on available data, exercise echocardiography gets a class IIa recommendation for assessment of MR patients (7). Several smaller studies have reported different and conflicting predictors of FC (4,8-15). Some reports have suggested that age, gender, and exercise cardiac output, early diastolic mitral annulus velocity, preoperative sinus rhythm, LV diastolic dysfunction, atrial fibrillation, forward stroke volume, exercise right ventricular systolic pressure (RVSP), low left atrial (LA) strain, brain natriuretic peptide predict FC, while LV ejection fraction, LA size, LV dimensions, mitral effective regurgitant orifice area (EROA), mitral regurgitant fraction, rest and exercise RVSP did not predict FC